Has your OER or NCOER ever been based off a single event?

Anyone ever been told their OER/NCOER was based off a single event? Rumor circulating through my Brigade at the moment is that our OERs and NCOERs may be based off our success or failure during Division inspections of our special emphasis programs (AA&E, Supply Security, Unit Security, Battalion Information Security, Intelligence Oversight, etc.) I believe it's just designed to ensure effort is being put into our areas, but I'm curious if anyone else has ever experienced this...warning?